A wireless communication system generally includes a base station and a user equipment (User Equipment, hereinafter referred to as UE for short). The base station and the UE communicate with each other through electromagnetic waves transmitted and received by a wireless transceiver. A signal sent by the base station to the UE is referred to as a downlink (downlink, DL for short) signal. A signal sent by the UE to the base station is referred to as an uplink (uplink, UL for short) signal. Each wireless transceiver has particular coverage. One base station may communicate with multiple UEs in its coverage. Generally, the coverage of a base station is referred to as a cell. The total traffic supported by a cell is referred to as cell capacity. Multiple base stations may be correlated with each other according to a particular rule to form a wireless communication network with larger coverage. The sum of cell capacity of each cell included in the wireless communication network is system capacity of the wireless communication network.
An existing networking solution for improving system capacity is combining the multi-sector method with the multi-antenna method. The multi-sector method is dividing a cell into multiple physical sectors and improving frequency reusability by using multiple sectors, thereby improving system capacity. The multi-antenna method is performing communication by using the MIMO (Multiple Input Multiple Output, multiple input multiple output) technology to improve system capacity. Under the condition that the total number of antennas in a base station remains unchanged, a larger number of sectors corresponding to the base station results in a smaller number of antennas of each sector. In this case, frequency reusability brought by the number of sectors is higher, and an MIMO gain brought by the number of antennas is lower. A smaller number of sectors corresponding to the base station results in a larger number of antennas of each sector. In this case, frequency reusability brought by the number of sectors is lower, and an MIMO gain brought by the number of antennas is higher.
The inventor of the present invention finds that: in a frequency division duplex (Frequency Division Duplex, FDD for short) system, under the condition that the total number of antennas is the same, for downlink communication, a system capacity gain brought by frequency reuse is higher than that brought by the MIMO gain, whereas for uplink communication, the system capacity gain brought by frequency reuse is lower than that brought by the MIMO gain. That is, under the condition that the total number of antennas is the same, the system capacity gain is higher when more sectors are used in the downlink, whereas the system capacity gain is higher when fewer sectors are used in the uplink. As may be seen from the above, in the prior art, a conflict exists between uplink and downlink processing for improving system capacity.